In the cosmetic industry, dyestuffs have been employed in various forms primarily for the coloration of human hair. In such applications, numerous limitations have been placed upon the dye systems employed based upon considerations mandated by concern for human safety and the need to avoid exposure to substances having high toxicity, as well as other adverse effects which may result to the user's skin or hair tissue.
Bismuth containing dyeing systems have heretofore been employed for use in the coloration of human hair, particularly for applications involving the darkening of graying hair either in men or women.
In applications involving bismuth containing dyeing systems, a variety of different additives and enhancers have been suggested to improve the effect achieved. Numerous mechanisms of dyeing and dye formations have been put forth in this art.
In spite of the long history of the dyeing art, a completely satisfactory dyeing system for human hair has yet to be achieved. Amongst the drawbacks of various known hair dyeing systems are the relatively poor level of coloration imparted to the hair subjected to dyeing, and/or the relative efficiency and ease with which the dye is imparted to the hair fibers to achieve the desired coloration.
While a considerable degree of effort has been expended in seeking to achieve improved dyeing systems for human hair, in general, the known means of enhancing the basic hair dyeing process have only met with limited success.
Such means as have been developed, while helpful in improving one or more perceived inadequacies of a given dyeing system, often render the remaining characteristics of such systems more troublesome, or do nothing to improve similar aspects in other dyeing systems which have also been used for human hair.
Exemplary of the state of the art as to various known systems for dyeing human hair and related materials are the following:
U.S. Pat. No. 2,185,467, which issued on Jan. 2, 1940, to Kritchevsky, discloses the use of formamide or derivatives thereof with organic dyes to enchance the adhesion of such dyes to human hair. No mention is made of the use of bismuth containing dyes nor the advantages to be achieved utilizing the catalysts of the present invention with such dyeing systems.
U.S. Pat. No. 2,983,651, which issued on May 9, 1961, to Seemuller, relates to the dyeing of animal fibers involving the use of a solution of a direct dye in an aqueous organic solvent which is chemically indifferent with respect to the dye and to the product to be dyed. Although a number of dyeing systems are defined as applicable utilizing the disclosed invention, no mention is made of the use of a bismuth containing dyeing system such as that which is the subject of the instant application.
U.S. Pat. No. 3,075,821, which issued on Jan. 29, 1963, discloses the use of a two-step process for dyeing a keratinous material involving the application of metal salt such as that of cobalt, nickel, copper, zinc, palladium, silver, cadmium, or mixtures thereof in aqueous solution and the subsequent treatment of the keratinous fibers in a solution of dithio-oxamide. No disclosure is made of the use of a bismuth containing dyeing system such as that disclosed in the instant application.
U.S. Pat. No. 3,206,363, which issued on Sept. 14, 1965, to Lecher, et al., is directed to use of certain alkyl derivatives of urea in dyeing systems utilized for dyeing either natural or synthetic polyamide fibers, including living human hair, in order to prevent the staining of the scalp and/or scalp irritation which was attendant upon the use of various other art employed solvents. No teaching is apparent as to the use of a bismuth containing dye system having the enhanced characteristics displayed by the compositions of the present invention.
U.S. Pat. No. 3,402,986, which issued on Sept. 24, 1968, to Zviak, et al., relates to a method of dyeing hair at ambient temperature using a direct dye dispersed in a aqueous medium containing not more than 10% by weight of a water miscible alcohol selected from the group of alcohols which are colorless, non-toxic and chemically indifferent to the dye and the hair.
U.S. Pat. No. 3,632,290, which issued on Jan. 4, 1972, to Tucker is directed to a composition for the dyeing of human hair involving the use of mixtures of aryl and alkyl glycol eithers in aqueous media as carriers and solubilizers for normally water-insoluble dyes involving a broad range of dyestuffs. No specific teaching is apparent as to the bismuth containing dye system disclosed in the present application.
U.S. Pat. No. 3,822,112, which issued on July 2, 1974, to Zviak, et al., is directed to a method of dyeing human hair which comprises applying a hair dye composition comprising an aqueous solution of a direct dye which can be either an azo dye, a basic dye or a nitro dye in combination with from 0.5 to 8% by weight of 2-phenoxyethanol and 3.5 to 12% by weight of ethyl glycol acetate. Again, no mention is made of the use of a bismuth containing dye system such as that which is the subject of the instant application, nor of the use of the subject catalyst components disclosed herein.
None of the foregoing prior art teachings suggest the subject dyeing system or the method which is the subject of the instant application, which involves the utilization of a bismuth salt and a catalyst having the specific characteristics set forth in order to achieve a highly desirable increase in the efficacy of such a dye system when employed in the treatment of human hair.
It is, therefore, an object of the present invention to provide for a dyeing system for human hair comprising a bismuth salt and a catalyst component which achieves a substantial improvement in the efficacy in the coloration of human hair subjected to such a dyeing system, as compared with similar hair dyeing systems of the prior art.
It is a further object of the present invention to provide for a method of dyeing human hair comprising a bismuth salt and a catalyst component which will achieve a desired degree of coloration in the subject hair in a shorter period of time than has been heretofore possible utilizing similar such bismuth containing dyeing systems of the prior art.
These and other objects of th present invention will become apparent from the following description of the invention.